Florida Salt Marsh Vole

Beacham's Guide to the Endangered Species of North America
COPYRIGHT 2000 The Gale Group Inc.

Florida Salt Marsh Vole

Microtus pennsylvanicus dukecampbelli

Status

Endangered

Listed

January 14, 1991

Family

Muridae (Mouse and Rat)

Description

Short-tailed rodent with a blunt head and short ears.

Habitat

Salt marshes.

Reproduction

Litter of 4-6 young each year.

Food

Plant matter.

Threats

Limited range and low numbers.

Range

Florida

Description

The Microtus pennsylvanicus dukecampbelli (Florida salt marsh vole), a subspecies of the widespread meadow vole or field mouse (Microtus p. pennsylvanicus), is a short-tailed rodent about 6.5-7.5 in (17-19 cm) in total length. It is brownish black above and gray below, with a blunt head and short, rounded ears. It is distinguished from the meadow vole by its larger size, darker color, smaller ears, and certain skull characteristics.

Behavior

Because of its recent discovery and rarity, the life history and reproductive behavior of the Florida salt marsh vole have not been well studied. Typically, voles are active both day and night and are good swimmers. They feed on a great variety of plant matter, including grass, bark, seeds, and roots. The meadow vole is the most fecund mammal in North America. It reproduces throughout the year over much of its range and is capable of producing up to 17 litters of four to six young each year. After a gestation period of about 20 days, newborn voles grow rapidly and are weaned at about 14 days. They are an important prey for snakes, foxes, hawks, and owls.

Distribution

This subspecies was described in 1982 from specimens taken along the Waccasassa Bay in Levy County, Florida. It is thought to be a relict of a population dating from a period of the Pleistocene Era 8,000-30,000 years ago. In the past, lower sea levels exposed areas along the west coast of Florida that are now submerged. This coastal prairie and savannah provided habitat for voles. Meadow vole fossils have been found in Alachua, Citrus, and Levy counties. Today the closest meadow vole population is in Georgia, about 310 mi (500 km) to the north. The Florida salt marsh vole has not been found outside the single salt marsh on Waccasassa Bay. The marsh is privately owned, and at this time there are no plans for its development. Searches to discover additional populations in the coastal marshes of Levy and Citrus counties have proven unsuccessful. During the field work that discovered the subspecies, only 31 voles were taken. In a 1989 survey, only a single male vole was captured.

Threats

With its extremely limited range and small species population, the Florida salt marsh vole is
extremely vulnerable to extinction. Its decline appears to have been caused by naturally occurring climatic changes that have gradually turned coastal prairie habitat into woodland unsuitable for voles. This isolated subspecies is the last remnant of a much larger and wide-ranging population. It is likely that the recent drop in the Florida salt marsh vole population was caused by Hurricane Elena in August 1985. That storm remained stationary off the coast near Waccasassa Bay for 24 hours. The Florida salt marsh vole could be rendered extinct by another such hurricane.

Conservation and Recovery

Because of its designation as an Endangered species, the Army Corps of Engineers must consider the conservation of the Florida salt marsh vole when evaluating any permit request to alter the animal's salt marsh habitat.

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

Notes:

Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.

In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.